Viral-derived DNA invasion and individual variation in an Indonesian population of large flying fox Pteropus vampyrus

Here, we performed next-generation sequencing (NGS) on six large flying foxes (Pteropus vampyrus) collected in Indonesia. Seventy-five virus species in the liver tissue of each specimen were listed. Viral homologous sequences in the bat genome were identified from the listed viruses. This finding provides collateral evidence of viral endogenization into the host genome. We found that two of the six specimens bore partial sequences that were homologous to the plant pathogens Geminiviridae and Luteoviridae. These sequences were absent in the P. vampyrus chromosomal sequences. Hence, plant viral homologous sequences were localized to the hepatocytes as extrachromosomal DNA fragments. Therefore, this suggests that the bat is a potential carrier or vector of plant viruses. The present investigation on wild animals offered novel perspectives on viral invasion, variation, and host interaction.     

Effects of short- and long-term fasting on plasma and stomach ghrelin,and the growth hormone/insulin-like growth factor I axis in the tilapia, Oreochromis mossambicus

Ghrelin is a highly conserved peptide hormone secreted by the stomach, which is involved in the regulation of food intake and energy expenditure. Ghrelin stimulates growth hormone (GH) release, and increases appetite in a variety of mammalian and non-mammalian vertebrates, including several fish species. Studies were conducted to investigate the effect of feeding and fasting on plasma and stomach ghrelin, and the growth hormone/insulin-like growth factor I (IGF-I) axis in the Mozambique tilapia, a euryhaline teleost. No postprandial changes in plasma and stomach ghrelin levels or stomach ghrelin mRNA levels were observed. Plasma levels of GH, IGF-I and glucose all increased postprandially which agrees with the anabolic roles of these factors. Fasting for 4 and 8 d did not affect ghrelin levels in plasma or stomach. Plasma GH was elevated significantly after 4 and 8 d of fasting, while plasma IGF-I levels were reduced. Plasma ghrelin levels were elevated significantly after 2 and 4 wk of fasting, but no change was detected in stomach ghrelin mRNA levels. Four weeks of fasting did not affect plasma GH levels, although plasma IGF-I and glucose were reduced significantly, indicating that GH resistance exists during a prolonged nutrient deficit (catabolic state). These results indicate that ghrelin may not be acting as a meal-initiated signal in tilapia, although it may be acting as a long-term indicator of negative energy balance.     

Impaired Development of Somatotropes, Lactotropes and Thyrotropes in Growth-Retarded (grt) Mice

Congenitally primary hypothyroid growth-retarded (grt) mice exhibit a characteristic growth pause followed by delayed onset of pubertal growth. We characterized the developmental pattern of somatotropes, lactotropes and thyrotropes in the anterior pituitary, as well as plasma levels of their secretory hormones, in grt mice. Compared with normal mice, the weight of grt pituitary gland was similar at 8 weeks of age but significantly heavier after 12 weeks of age. Compared with normal mice, there were significantly fewer somatotropes in the grt pituitary until 8 weeks of age, but the number gradually increased up to 48 weeks. The number of lactotropes in grt mice was consistently lower than that in normal mice from 2 through 48 weeks, whereas the number of thyrotropes in the grt pituitary was consistently higher than in the normal pituitary. Thyrotropes in the grt pituitary exhibited hypertrophy and hyperplasia with less intensive thyroid-stimulating hormone (TSH) immunoreactivity than normal thyrotropes. In normal mice, the sum of the relative proportions of these cells plateaued at 8 weeks, where it remained up to 48 weeks of age. In grt mice, these proportions almost reached normal levels at 12 weeks of age but gradually declined after 24 weeks. Plasma growth hormone concentrations did not differ between grt and normal mice until 24 weeks of age. Compared with normal mice, grt mice exhibited significantly lower plasma prolactin and thyroxine levels but higher TSH levels. These findings indicate that development of somatotropes, lactotropes and thyrotropes in grt mice is impaired, being followed by altered hormone secretion.     

A morphological study of the thyroid gland in Risso's Dolphin,Grampus griseus

To accumulate histological information of cetaceans and basic information about metabolic systems of marine mammals, the thyroid gland of Risso's dolphins was examined by gross anatomical and light and electron microscopic observations. Gross anatomically, right and left lobes of the thyroid were not clearly discriminated, and no isthmus was observed. By light microscopy, irregular or oval follicular lumens were seen, and surrounded by follicular epithelial cells. By electron microscopy, the rough endoplasmic reticulum (rER) was seen adjacently to mitochondria at the basal and lateral regions of the follicular epithelial cells. RERs at the basal side of the cells sometimes contained flocculent material with the same electron density as the follicular lumen component. Microvilli were poorly developed at the apical surface of the cells. In the apical regions of the cells, there were typical Golgi complexes, multivesicular bodies, and granules with various size and electron density. The parafollicular cells were recognized among the follicular epithelial cells and in the interstitial regions but never protruded into the follicular lumen. These cells were present singly and/or formed clusters among the follicular epithelial cells, and often located adjacent to capillaries. They were obviously discriminated from follicular epithelial cells by higher electron density of their granules. In their cytoplasm, well-developed rERs, primary lysosomes, secondary lysosomes, multivesicular bodies, and phagosomes were recognized.     

Essential thrombocythemia in a dog

A two-year old male Welsh Corgi was referred for persistent thrombocytosis and occasional seizure. Hematological findings indicated marked thrombocytosis, eosinophilia, basophilia and moderate anemia. Bone marrow examination revealed marked megakaryocytic hyperplasia with morphologic abnormality. A diagnosis of essential thrombocythemia was made and the treatment was initiated with combination chemotherapy and maintained by prednisolone and busulfan. The dog successfully achieved complete remission on 100 days after initial presentation and has been good in health without chemotherapy since then.     

Effect of a novel rice fermented extract on gastric ulcers in horses

Gastric ulcers cause appetite loss, poor body condition, and colic in horses. This study investigated the protective effect of a rice fermented extract on the gastric mucosa in 17 healthy Thoroughbreds. For one month, horses in the rice fermented extract (nine horses) and control (eight horses) groups were orally administered a rice fermented extract (100%; 0.2 ml/kg, SID) and tap water (0.2 ml/kg), respectively. Gastric endoscopic images were obtained before and one month after rice fermented extract administration. The gastric ulcer score was lower after administration (median, 1; maximum, 2; minimum, 1) than before administration (median, 4; maximum, 4; minimum, 3) in the rice fermented extract group (P<0.05). In conclusion, the administration of a rice fermented extract for one month improves gastric mucosal lesions in Thoroughbreds with gastric ulcers.